The methods and systems described below provide for optimal treatment of fibroadenomas. A fibroadenoma is a benign tumor found in women's breasts. They are small, solid, round, rubbery masses that are typically found in breast self-exams or mammography. Fibroadenomas are harmless, but may be painful, palpable and emotionally bothersome, and they may mask other lesions that would otherwise be visible to mammography. Fibroadenomas are removed to alleviate pain and to alleviate the emotional burden of living with a breast lump. Even when the breast lump is confirmed to be a benign fibroadenoma, many women elect removal for these reasons. Typically, fibroadenomas are removed by lumpectomy, which is an open surgical procedure. Open surgical recision requires a fairly large incision, creates an unsightly scar on the breast and a scar inside the breast that interferes with mammography, and requires general anesthesia.
Sanarus, Inc. has proposed cryoablation of fibroadenomas in its PCT publication WO0197702. As proposed in that publication, cryoablation entailed the commonly preferred double freeze-thaw cycle consisting of 6 to 15 minute freezes followed by thawing until the internal cryoprobe temperature reaches 0° C. While that procedure is useful, the procedure described below provides suitable treatment with the advantages that a smaller iceball is created, it avoids ablating tissue surrounding the fibroadenoma that need not be ablated given the benign nature of the fibroadenoma, it limits the potential for damage to the skin overlying the fibroadenoma, and the resorption time for the ablated mass is greatly reduced.